NSF ARCHAEOMETRY: Human Use of Psychoactive Plants in Ancient North America: Experimental Method Development and Applications of Metabolomics Research in Archaeological Residue Analysis

This National Science Foundation Funded project led by Shannon Tushingham (WSU Anthropology), David Gang (WSU Institute for Biological Chemistry), and Jelmer Eerkens (UC Davis Anthropology) is focused on investigating human use of psychoactive smoke and drink plants—both archaeologically and in the present day. The research is conducted in collaboration with Tribal communities in the Plateau, Pacific Northwest Coast, California, and Canada. Our team is involved with the development of innovative methods to identify plant compounds in archaeological pipes and other artifacts. Other accomplishments include identifying tobacco (nicotine) in multiple pipes in Washington State and Idaho, and similar collaborative research with indigenous communities in California and First Nations tribes in British Columbia.

We apply archaeometric techniques to anthropological questions about the history of human use of psychoactive plants. Contact period peoples throughout the Americas widely used plants with stimulant or hallucinogenic properties (e.g., tobacco, coffee, cacao, cassina, datura) for medicinal, ceremonial or recreational purposes, yet surprisingly little is known about their use in the past. Liquid Chromatography-Mass Spectrometry (LC-MS) and Gas Chromatography-Mass Spectrometry (GC-MS) analysis offers a direct means to track ancient use of such plants by identifying alkaloid residues in ancient artifacts. We have been working on method development and refinement of residue extraction and analysis techniques. For example, our studies include work on smoke plants (in ancient pipes) and medicinal teas (in shell and pottery vessels) through identification of plant biomarkers, experimentation (“smoking” plants in experimental pipes, brewing medicinal beverages), and residue extraction from ancient specimens. A major focus is to develop the most powerful and least destructive methods possible that will have a wide range of future applications. Archaeological applications include studies directed at understanding the cultivation, range extension, and management of tobacco in western North America. For example, nicotine, a biomarker for tobacco (Nicotiana sp.), has been identified in ancient pipes from the southern Pacific Northwest Coast dating to as early as the 9th millennium AD., an area where the antiquity of tobacco smoking was, until now, unknown. In addition to tobacco, method development includes the chemical characterization of a suite of key smoke plants used by ethnographic hunter-gatherers (e.g. kinnikinnick or Arctostaphylos uva ursi, widely used by Pacific Northwest peoples) so that we may potentially identify prehistoric use of these plants. Other work includes identification of caffeine residues on shell and pottery vessels associated with Ilex vomitoria, a plant used to brew cassina, or the black drink, a caffeinated ceremonial tea famous for its use in purification rituals by elite males in the southeastern United States.